Study on creep characteristics and the isochronous stress–strain curve of Ni-Cr-Mo superalloy

ABSTRACTC276 superalloy is considered as a potential structural material for advanced nuclear reactor with good mechanical properties and corrosion resistance. High-temperature creep behaviour of C276 alloy was investigated in the temperature range of 650°C–700°C and at stresses of 140–430 MPa. A linear relationship was fitted between stress and minimum creep rate in the logarithmic coordinate system. The rupture time is analysed for life prediction in terms of isotherm extrapolation method, Monkman–Grant relation, and Larson–Miller parameter method, respectively. The isochronous stress–strain curves as a means of representing stress–strain–time relations under creep conditions were established by the parameter method. The fracture surface morphology of ruptured specimens was characterised by a scanning electron microscope to elucidate the failure mechanism.KEYWORDS: Ni-Mo-Cr superalloycreep rupturelife predictionisochronous stress–strain curve AcknowledgmentsThis work was supported by the National Natural Science Foundation of China (Grant nos. 52071330, 51901241), the Research Project of Shanghai Science and Technology Commission (19DZ2200300), the National Key Research and Development Program (Grant no. 2021YFB3700605), the Young Potential Program of Shanghai Institute of Applied Physics, Chinese Academy of Sciences and the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA02004210).Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThe work was supported by the National Natural Science Foundation of China [52071330]; National Natural Science Foundation of China [51901241]; the Strategic Priority Research Program of the Chinese Academy of Sciences [XDA02004210]; Research Project of Shanghai Science and Technology Commission [19DZ2200300]; the National Key Research and Development Program [2021YFB3700605].